제출 #610582

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
610582		lorenzoferrari	Split the Attractions (IOI19_split)	C++17	40 / 100	111 ms	17780 KiB

split

#include "split.h"
#include <bits/stdc++.h>
using namespace std;

vector<int> solve_tree(int n, array<int, 3> sc, array<int, 3> lb, vector<vector<int>> adj) {
    assert(sc[0] <= sc[1] && sc[1] <= sc[2]);
    vector<int> p(n, -1);
    vector<int> sz(n, 0);
    auto dfs = [&](auto&& self, int v) -> int {
        sz[v] = 1;
        for (int u : adj[v]) {
            if (u == p[v]) continue;
            p[u] = v;
            sz[v] += self(self, u);
        }
        return sz[v];
    };
    dfs(dfs, 0);
    assert(sz[0] == n);

    vector<int> ans(n, 0);
    array<int, 3> cnt{};
    auto colour = [&](auto&& self, int v, int c, bool risali) -> void {
        if (ans[v] != 0 || cnt[c] == sc[c]) return;
        ans[v] = lb[c];
        ++cnt[c];
        for (int u : adj[v]) {
            if (u == p[v] && !risali) continue;
            self(self, u, c, risali);
        }
    };

    for (int i = 0; i < n; ++i) {
        for (int c = 0; c < 2; ++c) {
            if (sc[c] <= sz[i] && sz[i] <= sc[c] + sc[2]) {
                colour(colour, i, c, false);
                colour(colour, p[i], c^1, true);
                for (int& x : ans) if (!x) x = lb[2];
                assert(cnt[0] == sc[0] && cnt[1] == sc[1]);
                return ans;
            }
        }
    }
    return ans;
}

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
    array<array<int, 2>, 3> v;
    v[0] = {a,1}, v[1] = {b,2}, v[2] = {c, 3};
    sort(v.begin(), v.end());
    array<int, 3> sc{v[0][0], v[1][0], v[2][0]};
    array<int, 3> lb{v[0][1], v[1][1], v[2][1]};

    vector<vector<int>> adj(n);
    for (int i = 0; i < (int)p.size(); ++i) {
        adj[p[i]].push_back(q[i]);
        adj[q[i]].push_back(p[i]);
    }

    if ((int)p.size() == n - 1) {
        return solve_tree(n, sc, lb, adj);
    }

    int min_deg = 0;
    for (int i = 0; i < n; ++i) {
        if (adj[i].size() < adj[min_deg].size()) {
            min_deg = i;
        }
    }
    array<int, 3> cnt{};
    vector<int> ans(n, 0);
    auto dfs = [&](auto&& self, int v) -> void {
        if (ans[v] != 0) return;
        for (int i = 0; i < 3; ++i) {
            if (cnt[i] < sc[i]) {
                ++cnt[i];
                ans[v] = lb[i];
                break;
            }
        }
        for (int u : adj[v]) {
            self(self, u);
        }
    };
    dfs(dfs, min_deg);

    return ans;
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36